I don't know any carmaker named "PSA"... PSA is the enterprise group that OWNS Peugeot and Citroën but PSA itself doesn't build cars under its designation. And AFAIK, GM only did it in a handfull of concept cars...
In the text it directly implies it was built for Shanghai: "People look at the city's first self-made luxury sports car (...) in Shanghai" Hard to be more explicit IMO.
You're mixing the notions "manufacturer" and "brand/make". If you take a look at a list of automobile manufacturers, you won't find there Peugeot or Pontiac. Instead, you'll find PSA and GM. Peugeot or Pontiac are brands.
"PSA Peugeot Citroën (previously Peugeot Société Anonyme) is a French automobile and motorcycle
manufacturer; these are sold under the Peugeot and Citroën
marques."
"General Motors Corporation , founded in 1908, is the world's second-largest
automaker. (...) In 2008, 8.35 million GM cars and trucks were sold globally under the following
brands: Buick, Cadillac, Chevrolet, GMC, GM Daewoo, Holden, Hummer, Opel, Pontiac, Saab, Saturn, Vauxhall and Wuling."
"The Shanghai Automotive Industry Corporation is a Chinese automobile
manufacturer which ranks the third among the "Big Five" Chinese automakers"
Q.E.D.
And the quote about the city in full is "People look at the city's first self-made luxury sports car at an international auto exhibition Monday in Shanghai." As you can see, the words "in Shanghai" refer to "auto exhibition" not "luxury sports car".